Finding the area..

Ok I'm studying for my final looking over my old tests and I can't remember how I got this one right. I tried going from 0, to pi/2, to pi/4, to 3pi/4, to pi using sinx to plug in each but I'm not getting the right answer. Help would be appreciated.

Find the area under the graph of f(x)=sinx from x=0 to x=pi, using the four rectangles with the sample points to be the left endpoints.The answer = 1.896

Ok I'm studying for my final looking over my old tests and I can't remember how I got this one right. I tried going from 0, to pi/2, to pi/4, to 3pi/4, to pi using sinx to plug in each but I'm not getting the right answer. Help would be appreciated.

Find the area under the graph of f(x)=sinx from x=0 to x=pi, using the four rectangles with the sample points to be the left endpoints.The answer = 1.896